More than 70% of smokers who receive first-line therapies relapse within 6 months. Thus, alternative and complementary smoking-cessation therapies are needed. Given its success in treating anxiety and alcohol disorders, Attentional bias modification (ABM), a computer-delivered intervention, has been proposed to treat nicotine dependence. ABM reduces the attentional bias (AB) towards smoking cues that develops over time as a result of conditioning processes through which smoking cues become strongly motivationally salient. ABM with smokers has been attempted, but with limited success. We have identified three weaknesses with the smoking ABM approaches to date: (1) Existing smoking ABM studies have relied on only a single laboratory training session, falling short of a realistic and generalizable assessment of the technique's potential to influence neurobiological mechanisms associated with AB and smoking behavior; (2) No published smoking ABM study has evaluated the generalizability of ABM to AB experienced in multiple environments, to AB across multiple modalities, and to alter AB in the long-term; (3) No previous study has examined the potential additive benefits of ABM on first-line smoking cessation therapy. The objective of this application is to determine the feasibility of smartphone-delivered, in-home ABM to reduce AB to smoking cues and to modify smoking behavior in the short- and long-term. Participants will be 250 treatment-seeking smokers, who will receive 8 weeks of NRT after completing either ABM (AB away from smoking cues and toward neutral cues) or sham training daily for 2 weeks. The first aim of this study is to identify the impact of in- home ABM on AB and the second aim is to identify the impact of in-home ABM on smoking behavior. The significance of this project is a new non-pharmacological intervention that normalizes AB and smoking behavior in treatment-seeking smokers that can be used as an adjunct to first-line cessation therapies. The innovations of this project are as follows: 1) we will be the first to administer multiple-session n-home ABM training using smartphones which offers the potential of maximizing ABM's effects to smokers' naturalistic environments; 2) we will be the first to evaluate the impact of ABM in conjunction with a first-line smoking cessation therapy (NRT); 3) we will be the first study to directly assess the generalizability of ABM on AB measured using multiple modalities, including central nervous system indicators of changes using ERP methodology, which its high spatial resolution is ideal for examining early attentional processes that RT cannot duplicate and 4) by using multiple sessions, we will be able to assess trajectories of change in AB over time to determine the optimum number of ABM training sessions. We anticipate that our study will have a positive impact on smoking cessation treatment by identifying an innovative low-cost intervention that alters AB and smoking behavior in treatment-seeking smokers, which would suggest a promising new avenue for future smoking cessation clinical trials.